Dual-lumen suction catheter with smaller diameter vent lumen having multiple apertures therein

ABSTRACT

A dual-lumen suction catheter is disclosed consisting of a longitudinally extending pliable tube having separate and independent suction and vent lumens. The proximal end of the catheter has a first open end for the suction lumen and a second, separate open end, for the vent lumen. The catheter is provided with an opening at its distal end through which fluids to be withdrawn from the organ of a patient enter the suction lumen. A plurality of spaced-apart apertures situated in the distal portion of the catheter extend from within the vent lumen through the wall of the pliable tube to the outside surface of the catheter, the apertures being longitudinally displaced from each other and from the distal tip of the catheter. The plurality of apertures are independent of and separate from the suction lumen.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.08/677,390, filed Jul. 9, 1996 and entitled Dual-Lumen Suction Catheterwith Multiple Apertures in the Vent Lumen.

BACKGROUND OF THE INVENTION

The present invention relates to medical suction catheters and, inparticular, to suction catheters of the dual-lumen type. This inventionis related, in part, to Applicant's copending application Ser. No.441,548, filed May 15, 1995, now U.S. Pat. No. 5,643,230, and entitled"Nasogastric Suction Catheter", and copending application Ser. No.08/677,390, filed Jul. 9, 1996 and entitled Dual-Lumen Suction Catheterwith Multiple Apertures in the Vent Lumen.

The conventional dual-lumen medical suction catheter is specificallydesigned for the evacuation of the contents of the internal organs of apatient for example, the urinary bladder, the gall bladder, the stomachand the small intestines. Such catheters are used during emergencysurgery in trauma cases, during the time the patient is in intensivecare, in recovery and, in certain cases, until the patient is releasedfrom the hospital.

Since reduced air pressure is present within the suction lumen of theconventional dual-lumen suction catheter, produced by action of thesuction pump, it is important that the vent lumen provide air atatmospheric pressure, or above, within the organ of the patient fromwhich the contents are to be evacuated to assure satisfactory operationduring the suctioning process.

Due to a number of problems, conventional dual-lumen suction cathetersdo not always perform in the manner desired. One such problem is theblockage of the suction lumen itself during the suctioning procedures.This occurs when the larger particles within the organ pass through thesuction apertures into the suction lumen. If these particles are largerin size and occur in large numbers, the suction lumen becomes blockedand suctioning ceases. It then becomes necessary to flush out theblocked suction lumen, either by air under pressure or by forcing aliquid solution down through the suction lumen from its open proximalend.

Another problem occurs when the vent lumen of the catheter becomesoccluded or blocked, thereby preventing air to enter the organ to beevacuated. This blockage effectively arrests the suctioning process. Onesolution to vent lumen blockage is proposed in U.S. Pat. No. 3,982,540where an apparatus is disclosed for providing a regulated, smallpositive air pressure into the open proximal end of the vent lumen. Thispatent also discloses a modified dual-lumen suction catheter withapertures situated between the vent and suction lumens at the distal endof the catheter to aid in clearing the blockage of suction apertures.

An additional problem, known in the medical arts as gastric reflux,occurs when the contents of the stomach of a patient are forced to enterthe vent lumen through a vent aperture or opening by the suddencompression of the walls of the stomach of the patient. This problemoccurs when the air pressure within the stomach becomes greater than thenormal air pressure within the vent lumen; namely, atmospheric pressure.When gastric reflux occurs, part of the contents of the stomach can beforced up through the vent lumen and out of its open proximal end on tothe patient. One simple solution to this problem has been to block theopen proximal end of the vent lumen with a plug or cap, although this isfrequently overlooked. A proposed solution is suggested in U.S. Pat. No.4,735,607 wherein a one-way valve is disclosed for insertion into theopen proximal end of the vent lumen, the valve allowing air to enterinto the vent lumen but preventing air or fluids from escaping.

BRIEF SUMMARY OF THE INVENTION

The present invention introduces an improved suction catheter of thedual-lumen type to minimize and to alleviate the above-mentionedproblems of vent-lumen blockage and gastric reflux by providing thesuction catheter with a plurality of vent apertures spaced apartlongitudinally from the open distal end of the suction lumen by adistance sufficient to assure that at least one of the vent apertureswill be positioned above the level of the contents to be withdrawn fromthe organ of the patient.

Each of the plurality of vent apertures extends from within the ventlumen out through the wall to the outside surface of the catheter and isseparate from and independent of the suction lumen and the suctionapertures. Each of the plurality of vent apertures is adapted for thepassage of air, at atmospheric pressure or above, from the vent lumeninto the organ of the patient whether the vent lumens are above or belowthe level of the contents of the organ being withdrawn. The ventapertures are spaced apart from each other and may vary in number. Aslong as one of the plurality of spaced-apart vent apertures remainsabove the level of the contents of the organ, vent lumen blockage doesnot occur, and gastric reflux of the contents within the organ into thevent lumen is eliminated.

A primary object of the invention is to provide an improved suctioncatheter of the dual-lumen type wherein the vent lumen is provided witha plurality of longitudinally spaced-apart vent apertures in the distalend portion of the catheter to assure that adequate air pressure ispresent within the organ of a patient as the contents of the organ arebeing withdrawn into the open distal end of the suction lumen of thesuction catheter by the suction pump.

Another object of the invention is to provide an improved gastricsuction catheter of the dual-lumen type having a plurality oflongitudinally spaced-apart apertures into the vent lumen, spaced fromthe open distal end of the catheter to minimize the possibility ofblockage of the vent lumen while the open distal end of the suctioncatheter is intubated within the stomach of the patient.

Still another object is to provide a dual-lumen nasogastric suctioncatheter having a plurality of longitudinally spaced-apart aperturesinto the vent lumen, spaced from the distal end of the catheter toprevent gastric reflux of the contents of the stomach of a patient intothe vent lumen while the suction catheter remains positioned within thestomach of the patient.

The above objects of and the brief introduction to the invention will bemore fully understood, and further objects and advantages will becomeapparent from a study of the following detailed description inconnection with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of one embodiment of the suction catheter of theinvention having three spaced-apart vent apertures into the vent lumen.

FIG. 2 is an enlarged cross-section representation of the vent aperturesof FIGS. 1 and 3 taken along the lines 2--2.

FIG. 3 is a side view of a nasogastric suction catheter in accordancewith the invention with spaced-apart vent apertures into the vent lumen.

DESCRIPTION OF THE INVENTION

The medical suction catheter 11 of the invention illustrated in FIG. 1consists of a long, slender, hollow, flexible tube 12 having independentfirst and second lumens 13 and 14 extending the length of tube 12. Thefirst or suction lumen 13 is larger than the second vent lumen 14, andthe two lumens are separated one from the other. The vent lumen isidentified by the close-spaced parallel broken lines inside the outersurface of flexible tube 12.

The proximal end 15 of suction lumen 13 is enlarged and is open forcoupling to the conventional medical suction pump by means of a suctionhose. The proximal end 16 of the smaller vent lumen 14 is open toatmospheric pressure or to a separate source of air under a smallpositive pressure.

The distal end of suction catheter 11 is covered with a short, soft,hollow and ridged bullet-shaped member 19 having a number of recessedsuction apertures 17. The contents to be withdrawn from the organ of apatient pass through suction apertures 17 into the open distal end oftube 12 and into suction lumen 13. Suction aperture 17 may be circularor oval in shape and may have a cross-sectional area less than thecross-sectional area of suction lumen 13 to minimize the possibility ofblockage of suction lumen 13.

Flexible tube 12 may be made of rubber tubing or medically approvedpolyvinylchloride tubing. The short, soft, hollow bullet-shaped member19 may be molder of polyvinylchloride powder and, preferably, issomewhat softer and more resilient than flexible tube 12. Hollow,bullet-shaped member 19 may be made opaque to x-rays by adding a smallamount of barium sulfate to the polyvinylchloride powder.

Three vent apertures 21, 22 and 23 extend from within vent lumen 14 outthrough the wall to the outside surface 20 of flexible tube 12. Thesevent apertures may be punched or cut into vent lumen 14 from the outsidesurface 20 of flexible tube 12 by any suitable means, and they becircular, oval or slotted in shape. The cross-sectional area of eachvent aperture is approximately equal to the cross-sectional area of ventlumen 14.

Vent apertures 21, 22 and 23 are spaced-apart from each other and fromthe suction apertures 17 in hollow, bullet-shaped member 19. Thedistance between adjacent vent apertures and the distance between ventaperture 21 and suction apertures 17 may vary depending upon thephysical size of suction catheter 11 and the size, as well as the age,of the patient. The distance between adjacent vent apertures and betweenvent aperture 21 and suction apertures 17 is also determined by anotherfactor; namely, the organ of a patient into which the suction catheteris to be intubated. In particular, the distance between adjacent ventapertures 21, 22, and 23 is approximately equal to the distance betweenthe open distal end of suction lumen 13 in flexible tube 12 and the mostdistal vent aperture 21. Upon intubation of the organ of a patient to beevacuated, in accordance with the invention, at least one of the ventapertures 21, 22 or 23 should be positioned above the level of thecontents to be withdrawn. Since it is not always easy for the physicianto know in advance the physical size, exact shape and condition of theorgan, a plurality of vent apertures is recommended to assure that atleast one is properly positioned. The reasons for this positioning willbe discussed hereinbelow.

The cross-sectional representation of vent apertures 21, 22 and 23 isillustrated in FIG. 2. As can be seen, the area of vent lumen 14 isappreciably smaller than the area of suction lumen 13. Thecross-sectional area of vent apertures 21, 22 and 23 can be controlledby the length as well as the width and shape of the punch used to formthese apertures.

FIG. 3 illustrates a nasogastric suction catheter 31 having a longflexible tube 32 with suction lumen 33 and vent lumen 34. A short, soft,hollow distal end member 30 has its open proximal end bonded to the opendistal end of flexible tube 32. Hollow distal end member 30 is similar,in part, to the corresponding hollow distal end member 30 of Applicant'scopending application Ser. No. 441,548, filed on May 15, 1995, now U.S.Pat. No. 5,643,230. Hollow distal end member 30 is provided with ridges35, troughs 36 and a number of suction apertures 37.

The distal end 39 of hollow distal end member 30 is hollow, of bulletshape, and is resiliently collapsible when pressed upon an obstruction.It returns to its original shape upon release of any obstructive force.Hollow distal end member 30 may be made x-ray opaque and may be composedof soft, medically approved polyvinylchloride.

Three vent apertures 21, 22 and 23, the same as illustrated in FIG. 1,extend from within vent lumen 34 out through the wall to the outsidesurface of flexible tube 32. Vent apertures 21, 22 and 23 are spacedfrom each other and from suction apertures 37 in the manner and for thesame reasons discussed above in connection with suction catheter 11 ofFIG. 1.

The physician, when intubating the stomach of a patient with thenasogastric suction catheter 31 of FIG. 3, will be careful to observethe passage of soft, hollow distal end member 30 through the naris, downthrough the esophagus, past the esophago-gastric sphincter and into theupper part of the stomach. If the air pressure or the gas pressurewithin the stomach is above atmospheric pressure, the air or gas willenter one of the suction apertures 37 and into such lumen 33 and passout of the open proximal end of catheter 31. If the suctioning procedurehas commenced, fluids within the upper part of the stomach may enter oneor more of the lower suction apertures 37 and into suction lumen 33 andbe withdrawn, due in part to the collapsing of the wall of the stomach.As the withdrawal of stomach fluids continues, the using physician maylower soft, hollow distal end member 30 farther into the central portionof the stomach. Once vent aperture 21 has passed the esophago-gastricsphincter at the upper end of the stomach, air at atmospheric pressureis free to pass down vent lumen 34 and pass out through vent aperture 21into the stomach of the patient. Normal suctioning of the contents ofthe stomach may continue until air in the stomach begins to enter theupper suction apertures 37 of the catheter. When this condition isobserved by the using physician, as by air bubbles in the withdrawnfluids, the soft, hollow distal end member 30 should be lowered evenfarther into the central area of the stomach, resulting in the passageof vent aperture 22 past the esophago-gastric sphincter and into theupper end of the stomach. Two vent apertures 21 and 22 now arepositioned within the stomach. Soft, hollow distal end member 30 may belowered even farther into the stomach or moved around within the stomachto remove as much of the contents of the stomach as possible beforeterminating the suction process.

Nasogastric suction catheter 31 of FIG. 3 is frequently left in placewithin the stomach of the patient upon completion of the suction processand while the patient remains in intensive care or recovery. If, for anyreason, there is a build-up of fluids within the stomach, either byfeeding or from bleeding, or from normal gastric fluids, during thisperiod, the possibility of gastric reflux by a sudden compression forceupon the fluids by the stomach itself may force the fluids to entersuction apertures 37 and suction lumen 33. While any such fluids maytravel the length of the catheter and exit the open proximal end of thesuction lumen, they do not enter the vent aperture or apertures as longas at least one vent aperture remains positioned above the level of thefluids within the stomach. The explanation for this feature ofApplicant's invention is that the force created within the stomachacting upon the fluids is by an increase in air or gas pressure withinthe stomach itself, and this increase in air or gas pressure ismanifested into the vent lumen by its passage through one or more of thevent apertures 21, 22 or 23. This results in the air within the ventlumen being above that of air at atmospheric pressure and at the samepressure as the compressed air within the stomach above the level of thefluids. Accordingly, stomach fluids are restrained from entry into thevent lumen and must pass, instead, into suction lumen 33 through any ofsuction apertures 37, the air within the open suction lumen 33 being atatmospheric pressure.

It may be noted that the distal tip of vent lumen 14 of suction catheter11 of FIG. 1, as well as the distal tip of vent lumen 34 of nasogastricsuction catheter 31, may be left open or may be sealed closed, as bymeans of a cemented plug. Whether the distal tip of the vent lumen isopen or is closed, gastric reflux of the fluids within the stomach intothe vent lumen is prevented as long as at least one vent apertureremains above the level of the fluids within the stomach.

Since many changes may be made in the above-described device and manydifferent embodiments of this invention could be made without departingfrom the scope thereof, it is intended that all matter contained in theabove description or shown in the accompanying drawings shall beinterpreted as illustrative and not in a limiting sense.

I claim:
 1. A medical suction catheter comprising in combination:(a) along, flexible tube member having independent first and second lumensextending the entire length of said tube member, the first lumen being asuction lumen and the second lumen being a vent lumen, thecross-sectional area of said suction lumen being larger than thecross-sectional area of said vent lumen; (b) said tube member havingfirst and second open proximal ends, the first open end for said suctionlumen and the second open end for said vent lumen; (c) said tube memberhaving an open distal end for said suction lumen for receiving thecontents to be withdrawn from the organ of a patient; and (d) aplurality of vent apertures situated near the distal end of said tubemember, said plurality of vent apertures being spaced apartlongitudinally from each other and from the distal end of said tubemember, each of said plurality of spaced-apart vent apertures extendingfrom within said vent lumen out through the wall to an outside surfaceof said tube member, each of said plurality of spaced-apart ventapertures being adapted for the passage of air from within said ventlumen into the organ of the patient as the contents of the organ arebeing withdrawn from the organ into said open distal end of said suctionlumen, the distance between said spaced-apart vent apertures beingapproximately equal to the distance between said open distal end of saidsuction lumen and the vent aperture nearest said open distal end of saidsuction lumen; (e) wherein the cross-sectional area of each of saidplurality of spaced-apart vent apertures is approximately equal to thecross-sectional area of said vent lumen.
 2. The medical suction catheteras defined by claim 1 wherein the vent lumen at the distal end of saidlong, flexible tube is sealed closed.
 3. The medical suction catheter asdefined by claim 1 wherein said plurality of spaced-apart vent aperturessituated near the distal end of said long, flexible tube includes atleast two spaced-apart vent apertures, and wherein at least one of saidtwo spaced-apart vent apertures is located at a distance from said openend of said suction lumen by an amount sufficient to assure that it isabove the level of the contents in the organ of the patient as thecontents in the organ are being withdrawn through said suction lumen. 4.The medical suction catheter as defined by claim 1 wherein saidplurality of spaced-apart vent apertures situated near the distal end ofsaid long, flexible tube includes at least three spaced-apart ventapertures, and wherein at least one of said three spaced-apart ventapertures is spaced from said open end of said suction lumen by adistance sufficient to assure that air within the said vent lumen willpass through said one vent aperture into the organ of the patient abovethe level of the contents to be withdrawn from the organ.
 5. In amedical suction catheter comprising(a) a long, flexible tube memberhaving independent first and second lumens extending the entire lengthof said tube member, the first lumen being a suction lumen and thesecond lumen being a vent lumen of less diameter than said suctionlumen; (b) said tube member having first and second open proximal ends,the first open end for the suction lumen and the second open end for thevent lumen; (c) said tube member having an open distal end for thesuction lumen for receiving the contents to be withdrawn from the organof a patient, the improvement comprising a plurality of vent aperturessituated near the distal and of said tube member, said plurality of ventapertures being spaced-apart longitudinally from each other and from thedistal end of said tube member, each of said plurality of spaced-apartvent apertures extending from within said vent lumen out through thewall to an outside surface of said tube member, each of said pluralityof spaced-apart vent apertures being adapted for the passage of air fromwithin the vent lumen into the organ of the patient as the contents ofthe organ are being withdrawn from the organ into the open distal end ofsaid suction lumen of said catheter; (d) wherein the cross-sectionalarea of each of said plurality of spaced-apart vent apertures isapproximately equal to the cross-sectional area of said vent lumen.